Removal of Cr (VI) from effluent by Chemical method

In effluent sample, identification of Cr (VI) was done by spectroscopic and volumetric methods. In spectrophotometric method used Diphenyl carbazide reagent (Volgel, 1964). In volumetric method iodometric titration was used, and when analysis of electroplating effluent was carried out the concentration of Cr (VI) was 71.70 and pH 1.51. With the help of UV-Visible spectrophotometer, concluded that effluent having Cr (VI) in dichromate form in effluent. In first step Cr (VI) is convert to Cr (III) by using FeSO4 .5H2O. Throughout this process different parameters are affecting reduction reaction such as Effect dose of reducing agent, effect of pH, effect of amount of reducing agent, period required for achievement of reaction, effect of temperature, effect of stirring rate, etc. This reducing agents are effectively used for reduction of Cr (VI) to Cr(III). In the next step, comprehensive generalization of Cr (III) from resultant solution treated with FeSO4 .5H2O reducing agent was tried by using activated charcoal. We observed that pH at which Cr (III) get completely reduced at pH 6.5 on activated charcoal as an adsorbent. In presence of activated charcoal as a adsorbent nearly 99.98 % removal was achieved without oxidation of Cr (III) to Cr (VI).